“Biggest Loser” contestant Jim Germanakos belts out a medley, and Tara Costa makes the audience stand up for a workout in “The Diet Show.”Robert J Caputo

“Biggest Loser” contestant Jim Germanakos belts out a medley, and Tara Costa makes the audience stand up for a workout in “The Diet Show.” (
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Eager to shed those holiday pounds? You may want to check out “The Diet Show.” Not only might it provide some powerful motivation, but it’s the only show in town that at one point requires you to stand up and move.

Currently playing an irregular, open-ended run, the evening’s presented and co-written by comedian Gilbert Gottfried, who sadly isn’t around to deliver jokes. Instead, it features past winners and contestants of the reality show “The Biggest Loser,” which just kicked off a new season.

Recounting their success stories — and in at least one case, a not-so-successful story — the (relatively) slimmed down cast members describe their battles of the bulge in ways that are alternately moving and amusing.

Season 4 winner Bill Germanakos describes how he was finally motivated to lose weight when he couldn’t fit on a roller coaster with his young daughter. (He’s now a full-time motivational speaker.) Nicole Michalik, who lost 105 pounds, declares that she was determined to end her “abusive relationship” with food because she “wanted to be a hot slut.” And finalist Alfredo Dinten — named, he notes sadly, for a pasta with heavy cream sauce — talks about his life as a “food-truck stalker” and has an interesting take on pizza: “If you order the pie uncut, it only counts as one slice.”

Under Sean Pomper’s direction, some try a little too hard to be funny. Suzanne Mendonca, who’s inexplicably dressed as a bumblebee, recounts her childhood as a young beauty-pageant contestant — “I was the original Honey Boo Boo!” And Jim Germanakos — Bill’s twin brother — sings an overlong medley of advertising jingles extolling the joys of Oscar Mayer wieners and Rice-A-Roni.

Perky finalist Tara Costa, who says she once tipped the scales at 300 pounds, doesn’t confine herself to talking: She makes the audience stand up and wave their arms around, which won’t burn many calories but at least offers a welcome chance to stretch.

Some of the more entertaining moments in the show came from people who weren’t on the TV show. Plus-size model Krista Mays stripped down to her black underwear to show how difficult it is to squeeze into a pair of Spanx. And the aptly nicknamed comedian Jeff “The Fat Rat Bastard” Pirrami delivered a steady stream of hilarious one-liners. (“I tried taking speed to lose weight, but now I eat faster.”)

It was past winner Erik Chopin who gave the evening some emotional as well as physical heft.

“This isn’t really funny to me,” says the sad-eyed Chopin, who gained back the weight he lost — all 214 pounds of it — after his brief brush with stardom in Season 3. As likable as his self-loathing was palpable, he was a vivid reminder of how reality shows are capable of chewing up their subjects before spitting them out.